1. Field of the Invention
Embodiments of the invention relate generally to semiconductor packages. More particularly, embodiments of the invention relate to semiconductor packages including a transformer or an antenna.
A claim of priority is made to Korean Patent Application No. 2006-17903, filed Feb. 23, 2006, the disclosure of which is hereby incorporated by reference in its entirety.
2. Description of Related Art
As the size of portable electronic devices continues to shrink, the size of semiconductor packages mounted in the portable electronic devices must be scaled down accordingly. In addition, to increase the computational and/or memory capacity of circuits within the semiconductor packages, packaging techniques have been developed for mounting a plurality of semiconductor chips in a single semiconductor package. These packaging techniques include, for example, a multi chip package (MCP) technique, a multi-stack package (MSP) technique and a system in package (SIP) technique.
Circuits inside some semiconductor packages include an antenna for wireless communication with other circuits such as circuits within adjacent semiconductor packages. The performance of such an antenna tends to vary according to the antenna's length and structure. For example, the performance of an antenna for receiving low frequency signals tends to increase as the length of the antenna increases. That is, increasing the length of the antenna tends to enhance the antenna's low frequency characteristics.
Semiconductor packages are often mounted in integrated circuit (IC) cards. A semiconductor package mounted in an IC card often includes a transformer comprising a solenoid coil for generating internal power based on external power supplied from an external system. In other words, where the IC card contacts a terminal unit of the external system, semiconductor packages in the IC card often generate appropriate internal power through internally mounted transformers.
Semiconductor packages including antennas are disclosed, for example, in U.S. Pat. No. 6,686,649 to Mathews et al., entitled “Multi chip Semiconductor Package with Integral Shield and Antenna,” and in U.S. Pat. No. 5,023,624 to Heckaman et al., entitled “Microwave Chip Carrier Package Having Cover-mounted Antenna Element.” In these semiconductor packages, a ground shield is formed around a semiconductor chip mounted on a package substrate, and an antenna is formed over the ground shield. The ground shield is designed to prevent electromagnetic interference between signals transmitted or received by the antenna and electrical signals produced by operations of the semiconductor chip. Unfortunately, however, the antenna and the ground shield are generally formed outside semiconductor packages surrounding the semiconductor chips. Hence, these antennas present an obstacle to reducing the overall size of semiconductor packages including the antenna and the ground shield.